The present invention relates generally to mobile robots and more particularly to robots capable of climbing and traversing horizontal, angled and vertical surfaces, including making transitions between the two.
It has been known in the art to provide mobile robots with the capability of moving in a two-dimensional plane to perform functions in the areas of national defense, surveillance and counter terrorism missions. Many successful robot platforms have emerged, but many of such mobile robots are limited to movement in a two-dimensional plane without wall-climbing capability.
Some robots have been developed with wall climbing capability by using magnetic devices, suction cups, or attraction force generated by a propeller. Applications for these types of climbing robots focused on inspection and maintenance tasks in hazardous environments, primarily in the nuclear, space, and chemical industries.
It has been a long-time desire to develop a miniature climbing robot with the ability to climb walls, walk on ceilings and transit between different surfaces, thus transforming the present two-dimensional world of mobile rovers into a new three-dimensional universe. For example, U.S. Pat. No. 5,839,532 to Yoshiji et al. discloses a vacuum wall walking apparatus having a frame and a plurality of leg mechanisms with suction cups. The frame is composed of a flexible member, making the frame bendable to conform to the profile of a curved surface when the device is used with a wall having such a curved surface.
Other robots developed for traversing nonplanar surfaces use articulated structure. For example, U.S. Pat. No. 5,551,525 to Pack et al. discloses a climber robot having front and rear legs joined together by a pivoting knee joint and having pivoting ankle joints at their distal ends. Pneumatic muscle pairs attached to each leg allow the robot to transition from the horizontal to the vertical plane.
U.S. Pat. No. 6,619,922 to Illingworth et al. discloses a vortex attractor for planar and non-planar surfaces using a so-called “tornado in the cup” technology. However this prior art has limited payload and has difficulty climbing from a wall to a ceiling or around a corner.
Accordingly, it would be desirable to improve upon the prior art by developing new concepts of modularity and mobility for a climbing robot capable of moving between nonplanar surfaces. It would be further desirable to overcome the limitations of prior art robots in terms of robot capability, modularity, control performance, and intelligence to perform various defense, security, and inspection missions.